US6366039B1 - Excimer laser device - Google Patents

Excimer laser device Download PDF

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Publication number
US6366039B1
US6366039B1 US09/553,466 US55346600A US6366039B1 US 6366039 B1 US6366039 B1 US 6366039B1 US 55346600 A US55346600 A US 55346600A US 6366039 B1 US6366039 B1 US 6366039B1
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Prior art keywords
fan
rotational speed
excimer laser
laser device
disk
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US09/553,466
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English (en)
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Shinichi Sekiguchi
Hiroyuki Shinozaki
Toshimitsu Barada
Toshiharu Nakazawa
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Ebara Corp
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Ebara Corp
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
    • F16C32/0406—Magnetic bearings
    • F16C32/044—Active magnetic bearings
    • F16C32/047—Details of housings; Mounting of active magnetic bearings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/036—Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/038—Electrodes, e.g. special shape, configuration or composition
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/03—Constructional details of gas laser discharge tubes
    • H01S3/038—Electrodes, e.g. special shape, configuration or composition
    • H01S3/0388—Compositions, materials or coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/22—Gases
    • H01S3/223—Gases the active gas being polyatomic, i.e. containing two or more atoms
    • H01S3/225—Gases the active gas being polyatomic, i.e. containing two or more atoms comprising an excimer or exciplex

Definitions

  • the present invention relates to an excimer laser device, and more particularly to an excimer laser device having a controller for detecting the rotational speed of a fan for generating a laser gas flow and controlling the rotational speed of the fan at a constant level.
  • FIG. 1 of the accompanying drawings schematically shows a conventional excimer laser device.
  • the conventional excimer laser device has a casing 101 filled with a laser gas, a preliminary ionizing electrode (not shown) disposed in the casing 101 for preliminarily ionizing the laser gas, and a pair of main discharge electrodes 102 disposed in the casing 101 for producing an electric discharge to make it possible to oscillate a laser beam.
  • the casing 101 also houses therein a cross-flow fan 103 for producing a high-speed gas flow between the main discharge electrodes 102 .
  • the cross-flow fan 103 has a rotatable shaft 104 projecting from opposite ends thereof and rotatably supported by a plurality of radial magnetic bearings 106 , 107 , 108 disposed on opposite sides of the casing 101 and an axial magnetic bearing 109 mounted on the radial magnetic bearing 106 .
  • the rotatable shaft 104 can be rotated by an induction motor 110 connected to an end thereof and disposed between the radial magnetic bearings 107 , 108 .
  • the casing 101 has a pair of windows 105 on its opposite ends for emitting the laser beam out of the casing 101 .
  • the laser gas contains a highly reactive halogen gas, e.g., a fluorine gas. Therefore, various chemical reactions are caused in the casing 101 , producing impurities such as HF, CF 4 , etc. These impurities are responsible for a reduction in the performance of the laser beam.
  • a highly reactive halogen gas e.g., a fluorine gas. Therefore, various chemical reactions are caused in the casing 101 , producing impurities such as HF, CF 4 , etc. These impurities are responsible for a reduction in the performance of the laser beam.
  • the excimer laser device fails to emit a laser beam which is stable over a long period of time.
  • One solution to the above problem is to control the discharge voltage applied between the main discharge electrodes 102 , 102 and to control the pressure of the filled laser gas to maintain the laser beam performance at a constant level or higher for a long period of time.
  • the load on the cross-flow fan 103 varies, and hence the rotational speed thereof also varies. Specifically, if the pressure of the filled laser gas increases, the load on the cross-flow fan 103 also increases, resulting in an increase in the slippage of the induction motor 110 which causes the rotational speed of the cross-flow fan 103 to decrease.
  • the rotational speed of the cross-flow fan 103 is reduced, the speed of flow of the lower gas between the main discharge electrodes 102 is reduced, with the consequence that the excimer laser device cannot oscillate at a high repetition rate.
  • the above drawback may be eliminated by setting the rotational speed of the cross-flow fan 103 in a high speed range for canceling out the speed reduction due to the increase of slippage of the motor 110 .
  • this approach is disadvantageous in that the power consumption by the cross-flow fan 103 increases when the pressure of the laser gas is high (the power consumption by the cross-flow fan 103 is proportional to the cube of the rotational speed thereof).
  • An alternative solution is to use a slippage-free synchronous motor, which is, however, complex in structure and high in cost.
  • an excimer laser device comprising a casing filled with a laser gas, a pair of main discharge electrodes disposed in the casing for producing an electric discharge to discharge-pump the laser gas at a high repetition rate, a fan for producing a high-speed laser gas flow between the main discharge electrodes, bearings, the fan having a rotatable shaft rotatably supported by the bearings, a motor for actuating the fan, rotational speed detecting device for detecting a rotational speed of the fan, and control device for controlling at least one of a voltage and a frequency to be supplied to the motor based on the rotational speed of the fan detected by the rotational speed detecting device, thereby to control the rotational speed of the fan at a constant level.
  • the rotational speed of the fan can be made constant irrespective of the pressure of the sealed laser gas.
  • the excimer laser device can therefore operate stably for oscillation at a high repetition rate. Furthermore, because the motor is operated efficiently at all times, the power consumed by the fan can be reduced.
  • the rotational speed detecting device may comprise a disk made of a magnetic material and having at least one slit defined therein, the disk being fixedly mounted on the rotational shaft of the fan and disposed in a hermetically sealed space communicating with the casing, a magnetic body disposed outside of the casing in confronting relationship to the disk with a can interposed therebetween, the magnetic body being narrower than the slit and having at least two protrusions, and a coil mounted on the magnetic body for inducing an electromotive force upon rotation of the disk, the control device comprising means for detecting the rotational speed of the fan from the electromotive force induced across the coil.
  • the rotational speed detecting device thus constructed is capable of detecting the rotational speed of the fan accurately.
  • the magnetic body with the coil mounted thereon is disposed outside of the casing with the can interposed therebetween, the coil which has poor corrosion resistance to the laser gas is not exposed to the laser gas, and does not deteriorate the laser gas.
  • the magnetic body partly or wholly comprises a permanent magnet.
  • the magnetic body thus arranged is effective in increasing the flux density of the magnetic flux of a magnetic circuit which is made up of the magnetic body and the disk.
  • the electromotive force induced across the coil is increased, resulting in an increased ability to detect the rotational speed of the fan. Because a bias current supplied to the coil for generating the magnetic flux can be reduced or eliminated, the rotational speed detecting device can be simplified in circuit arrangement and its power consumption can be reduced.
  • the rotational speed detecting device may comprise an air flow speed sensor disposed in the casing for detecting an air flow speed, thereby detecting the rotational speed of the fan from the air flow speed detected by the air flow speed sensor.
  • the air flow speed sensor can directly measure an air flow speed produced by the fan, and the control device can detect the rotational speed of the fan from the detected air flow speed, and control the rotational speed of the fan in order to keep the air flow speed constant.
  • FIG. 1 is an axial cross-sectional view of a conventional excimer laser device
  • FIG. 2 is an axial cross-sectional view of an excimer laser device according to an embodiment of the present invention
  • FIG. 3 is an enlarged fragmentary view of an encircled portion A of the excimer laser device shown in FIG. 2;
  • FIG. 4 is a diagram showing the results of a corrosion resistance test on permalloy against fluorine
  • FIGS. 5A-5F are views illustrative of the manner in which a rotational speed detecting circuit for detecting the rotational speed of a cross-flow fan of the excimer laser device operates;
  • FIG. 6 is a diagram illustrative of the manner in which an electromotive force generated across a coil of the rotational speed detecting circuit varies;
  • FIG. 7 is an axial cross-sectional view of an excimer laser device according to another embodiment of the present invention.
  • FIG. 8 is a diagram showing a calibration curve between fan rotational speeds and air flow speeds.
  • the excimer laser device comprises a casing 1 filled with a laser gas, a preliminary ionizing electrode (not shown) disposed in the casing 1 for preliminarily ionizing the laser gas, and a pair of main discharge electrodes 2 disposed in the casing 1 for producing an electric discharge to make it possible to generate an oscillation of a laser beam.
  • the casing 1 also houses therein a cross-flow fan 3 for producing a high-speed gas flow between the main discharge electrodes 2 .
  • the laser gas between the main discharge electrodes 2 is discharge-pumped to generate an oscillation of a laser beam.
  • the generated laser beam is emitted out of the casing 1 through windows 5 mounted on opposite ends of the casing 1 .
  • the laser gas is discharge-pumped, the laser gas is deteriorated and its discharge characteristics are lowered to the extent that no repetitive pumping could be performed.
  • the cross-flow fan 3 is operated to circulate the laser gas in the casing 1 for thereby replacing the laser gas between the main discharge electrodes 2 in each discharge cycle for stable repetitive pumping.
  • the cross-flow fan 3 has a rotatable shaft 4 extending axially therethrough and projecting from opposite ends thereof.
  • the rotatable shaft 4 is rotatably supported by a plurality of radial magnetic bearings 8 , 9 , 10 and an axial magnetic bearing 11 which are disposed in a cylindrical bearing housing 6 and a cylindrical motor housing 7 that are mounted on opposite sides of the casing 1 .
  • the rotatable shaft 4 can be rotated by an induction motor 12 disposed in the motor housing 7 .
  • An axial displacement sensor target 11 d and a slit disk 13 are mounted on an end of the rotatable shaft 4 in the bearing housing 6 , and placed in a hermetically sealed space which communicates with the casing 1 .
  • Each of the axial displacement sensor target lid and the slit disk 13 is made of permalloy (an Fe—Ni alloy containing 30 to 80% of Ni) which is highly corrosion-resistant to fluorine contained in the laser gas.
  • FIG. 4 shows the results of a corrosion resistance test on permalloy against fluorine. As shown in FIG. 4, permalloy has better corrosion resistance as the content of Ni is higher.
  • PC permalloy with an Ni content of 80% exhibits almost the same corrosion resistance as austenitic stainless steel SUS316L, it is preferable to construct the axial displacement sensor target lid and the slit disk 13 of PC permalloy.
  • the bearing housing 6 accommodates a U-shaped magnetic member 15 on which an axial displacement sensor 11 a and a coil 14 are mounted.
  • the U-shaped magnetic member 15 is positioned in confronting relationship to the axial displacement sensor target lid and the slit disk 13 .
  • a thin-walled cylindrical can 16 made of austenitic stainless steel such as SUS316L is secured as by welding to a surface of the U-shaped magnetic member 15 which is exposed to the laser gas.
  • the U-shaped magnetic member 15 on which the axial displacement sensor 11 a and the coil 14 are mounted is placed out of the hermetically sealed space by the thin-walled cylindrical can 16 . Accordingly, the axial displacement sensor 11 a and the coil 14 which are relatively poor in corrosion resistance are held out of contact with the laser gas.
  • the U-shaped magnetic member 15 comprises a permanent magnet 15 a and a yoke 15 b.
  • the axial magnetic bearing 11 comprises a right solenoid 11 b and a left solenoid 11 c which are axially spaced from each other in axially confronting relationship to each other, and mounted in the bearing housing 6 .
  • the right solenoid 11 b and the left solenoid 11 c which are positioned in contact with the laser gas, are preferably made of a magnetic material having a high saturation flux density. Therefore, the right solenoid 11 b and the left solenoid 11 c have respective cores made of PB permalloy whose saturation flux density is greatest among permalloys.
  • the right solenoid 11 b and the left solenoid 11 c have respective coils inserted in coil slots defined in the cores.
  • the right solenoid 11 b and the left solenoid 11 c are secured as by welding to respective thin-walled cylindrical cans 17 made of austenitic stainless steel such as SUS316L, such that the coils are held out of contact with the laser gas.
  • the cores of the right solenoid 11 b and the left solenoid 11 c have surfaces held in contact with the laser gas and processed for corrosion resistance, e.g., plated with an Ni coating.
  • the PB permalloy can be made as corrosion-resistant as the PC permalloy by being plated with an Ni layer.
  • the radial magnetic bearing 8 comprises a displacement sensor 8 a and a solenoid 8 b which are housed in the bearing housing 6 .
  • a thin-walled cylindrical can 18 made of austenitic stainless steel such as SUS316L is inserted in the displacement sensor 8 a and the solenoid 8 b and has its axially opposite ends secured in place as by welding.
  • the displacement sensor 8 a and the solenoid 8 b which comprise silicon steel sheets and copper wire coils that are poor in corrosion resistance to the laser gas, are held out of contact with the laser gas by the thin-walled cylindrical can 18 . Accordingly, the displacement sensor 8 a and the solenoid 8 b are protected against corrosion by the laser gas and prevented from contaminating the laser gas.
  • the radial magnetic bearing 8 also has a displacement sensor target 8 c and a solenoid target 8 d fixedly mounted on the rotatable shaft 4
  • the axial magnetic bearing 11 has a solenoid target 11 e fixedly mounted on the rotatable shaft 4 .
  • the displacement sensor target 8 c, the solenoid target 8 d, and the solenoid target 11 e are disposed in the hermetically sealed space in confronting relationship to the displacement sensor 8 a, the solenoid 8 b, the right solenoid 11 b, and the left solenoid 11 c.
  • the displacement sensor target 8 c, the solenoid target 8 d, and the solenoid target 11 e are made of permalloy (an Fe—Ni alloy containing 30 to 80% of Ni) which is highly corrosion-resistant to fluorine contained in the laser gas.
  • the displacement sensor target 8 c and the solenoid target 8 d cause an eddy current loss due to a magnetic field change produced upon rotation of the shaft 4 .
  • the displacement sensor target 8 c and the solenoid target 8 d are usually constructed of laminated thin sheets. However, a gas trap is formed between those laminated thin sheets, tending to contaminate the laser gas. If the surfaces of the laminated thin sheets cannot be plated with a uniform, highly adhesive Ni layer, then each of the displacement sensor target 8 c and the solenoid target 8 d may be constructed as an integral body of permalloy.
  • the solenoid target 11 e is constructed as an integral body of permalloy as its magnetic field does not change upon rotation of the shaft 4 .
  • the radial magnetic bearing 9 comprises a displacement sensor 9 a and a solenoid 9 b.
  • the motor 12 has a motor stator 12 a
  • the radial magnetic bearing 10 comprises a displacement sensor 10 a and a solenoid 10 b.
  • the displacement sensor 9 a, the solenoid 9 b, the motor stator 12 a, the displacement sensor 10 a, and the solenoid 10 b are placed in the motor housing 7 in fixed relatively positional relationship, and mounted on a thin-walled cylindrical can 19 made of austenitic stainless steel such as SUS316L which is inserted in the motor housing 7 has its axially opposite ends secured in place as by welding.
  • the displacement sensor 9 a, the solenoid 9 b, the motor stator 12 a, the displacement sensor 10 a, and the solenoid 10 b which comprise silicon steel sheets and copper wire coils that are poor in corrosion resistance to the laser gas, are held out of contact with the laser gas by the thin-walled cylindrical can 19 .
  • a water-cooling jacket 22 is mounted on an outer circumferential surface of the motor housing 7 for absorbing a heat loss of several 100 W generated by the motor 12 .
  • the motor stator 12 a has coils impregnated with an insulating material for efficiently dissipating the heat generated due to the resistance of the coils. Therefore, the motor stator 12 a has an increased ability to radiate the heat from the coils for preventing the motor 12 from burning.
  • the radial magnetic bearing 9 also has a displacement sensor target 9 a and a solenoid target 9 d.
  • the motor 12 has a motor rotor 12 b
  • the radial magnetic bearing 10 has a displacement sensor target 10 c and a solenoid target 10 d.
  • the displacement sensor target 9 c, the solenoid target 9 d, the motor rotor 12 b, the displacement sensor target 10 c, and the solenoid target 10 d are placed in the hermetically sealed space in confronting relationship to the displacement sensor 9 a, the solenoid 9 b, the motor stator 12 a, the displacement sensor 10 a, and the solenoid 10 b.
  • the displacement sensor targets 9 c, 10 c and the solenoid targets 9 d, 10 d are made of permalloy (an Fe—Ni alloy containing 30 to 80% of Ni), as with the displacement sensor target 8 c and the solenoid target 8 d.
  • the motor rotor 12 b is constructed of laminated silicon steel sheets and aluminum.
  • the motor rotor 12 b cannot be plated with a uniform, highly adhesive Ni layer for corrosion resistance.
  • a cylindrical can 20 is mounted on the outer circumferential surface of the motor rotor 12 b and secured as by welding to side plates 21 on axially opposite ends of the motor rotor 12 b, and the side plates 21 are secured as by welding to the rotatable shaft 4 .
  • the can 20 and the side plates 21 define a hermetically sealed space therein which accommodates the motor rotor 12 b for protection against contact with the laser gas.
  • the can 20 and the side plates 21 are made of austenitic stainless steel such as SUS316L.
  • the excimer laser device has a controller 30 comprising a rotational speed detecting circuit 31 , a processing circuit 32 , and an inverter 33 .
  • the coil 14 is electrically connected to the rotational speed detecting circuit 31 .
  • the inverter 33 is electrically connected to the coils of the motor stator 12 a for supplying electric energy to the motor stator 12 a for rotating the motor 12 .
  • the slit disk 13 has a pair of diametrically opposite slits 13 a defined therein. Since the slits 13 a defined in the slit disk 13 are responsible for balanced rotation of the slit disk 13 , it is preferable for the slit disk 13 to have an even number of slits 13 a.
  • the U-shaped magnetic member 15 with the coil 14 mounted thereon is disposed in confronting relationship to the slit disk 13 .
  • the U-shaped magnetic member 15 has a width smaller than the width of the slits 13 a.
  • a magnetic flux ⁇ 1 of a magnetic circuit created jointly by the slit disk 13 and the U-shaped magnetic member 15 is represented by the following equation (1):
  • ⁇ 1 NI / ⁇ ( l 1 / ⁇ 1 S )+( l 2 / ⁇ 2 S )+(2 X/ ⁇ 0 S ) ⁇ (1)
  • N the number of turns of the coil 14
  • I the current flowing through the coil 14
  • l 1 the length of the magnetic path of the U-shaped magnetic member 15
  • l 2 the length of the magnetic path of the slit disk 13
  • S the cross-sectional area of the magnetic path
  • X the cross-sectional area of the slit disk 13 and the U-shaped magnetic member 15 (see FIG. 5 C)
  • ⁇ 1 the magnetic permeability of the U-shaped magnetic member 15
  • ⁇ 2 the magnetic permeability of the slit disk 13
  • ⁇ 0 the magnetic permeability of the vacuum.
  • ⁇ 2 NI / ⁇ ( l 2 / ⁇ 1 S )+( l′ / ⁇ 0 S ) ⁇ (2)
  • FIG. 6 shows the manner in which the electromotive force induced across the coil 14 varies while the slit disk 13 is rotating at 3000 rpm. It can be seen from FIG. 6 that the induced electromotive force has a peak each time the magnetic flux passes through one of the slits 13 a.
  • the rotational speed detecting circuit 31 detects such peaks to detect the rotational speed of the shaft 4 .
  • the rotational speed detecting circuit 31 has a better detecting sensitivity if the magnetic flux as it passes through each of the slits 13 a varies to a larger extent and the generated electromotive force is greater. Therefore, the coil 14 is supplied with a bias current from the rotational speed detecting circuit 31 to generate a sufficient magnetic flux for inducing a desired electromotive force.
  • the U-shaped magnetic body 15 is constructed of the permanent magnet 15 a and the yoke 15 b to maintain a desired magnetic flux, thereby reducing or eliminating a steady current to flow in the coil 14 .
  • the coil 14 is connected to the rotational speed detecting circuit 31 , which detects an electromotive force induced across the coil 14 thereby to detect the rotational speed of the cross-flow fan 3 .
  • Information representing the detected rotational speed is sent from the rotational speed detecting circuit 31 to the processing circuit 32 , which determines an operating state of the cross-flow fan 3 .
  • the processing circuit 32 then controls the inverter 33 to supply electric energy at an optimum voltage and frequency to the coils of the motor stator 12 a, which gives an optimum revolving magnetic field to the motor rotor 12 b.
  • the excimer laser device can operate stably at a high repetition rate.
  • the U-shaped magnetic body 15 is employed.
  • another differently shaped magnetic body having two or more protrusions e.g., an E-shaped magnetic body, may be employed.
  • FIG. 7 shows an excimer laser device according to another embodiment of the present invention. Those parts of the excimer laser device shown in FIG. 7 which are identical to those of the excimer laser device shown in FIG. 2 are denoted by identical reference characters, and will not be described in detail below.
  • the casing 1 houses an air flow speed sensor 40 which is electrically connected to an air flow speed detecting circuit 42 in a controller 41 .
  • the controller 41 has a processing circuit 43 and an inverter 44 .
  • the inverter 44 is electrically connected to the coils of the motor stator 12 a for supplying electric energy to the motor stator 12 a for rotating the motor 12 .
  • the processing circuit 43 stores a calibration curve between fan rotational speeds and air flow speeds shown in FIG. 8 .
  • An air flow speed detected by the air flow speed sensor 40 is sent to the processing circuit 43 , which calculates the rotational speed of the cross-flow fan 3 from the detected air flow speed based on the calibration curve shown in FIG. 8 .
  • the processing circuit 43 determines an operating state of the cross-flow fan 3 .
  • the processing circuit 43 then controls the inverter 44 to supply electric energy at an optimum voltage and frequency to the coils of the motor stator 12 a, which gives an optimum revolving magnetic field to the motor rotor 12 b.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Lasers (AREA)
US09/553,466 1999-04-21 2000-04-19 Excimer laser device Expired - Lifetime US6366039B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP11397299A JP3766230B2 (ja) 1999-04-21 1999-04-21 エキシマレーザ装置
JP11-113972 1999-04-21

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US (1) US6366039B1 (fr)
EP (1) EP1047162B1 (fr)
JP (1) JP3766230B2 (fr)
KR (1) KR100654409B1 (fr)
DE (1) DE60040256D1 (fr)
TW (1) TW444423B (fr)

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US20020044588A1 (en) * 2000-09-19 2002-04-18 Takayoshi Ozaki Structure of reflux fan for excimer laser apparatus
US6519273B2 (en) * 2000-02-21 2003-02-11 Ebara Corporation Magnetic bearing and circulation fan apparatus
US6785314B2 (en) * 2000-06-08 2004-08-31 Ebara Corporation Electric discharge gas laser
EP1870971A1 (fr) * 2006-06-22 2007-12-26 Fanuc Ltd Oscillateur de laser à gaz
CN107210573A (zh) * 2015-03-12 2017-09-26 极光先进雷射株式会社 放电激励式气体激光装置
CN108352674A (zh) * 2015-12-01 2018-07-31 极光先进雷射株式会社 准分子激光装置

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JP2001111138A (ja) * 1999-10-04 2001-04-20 Ebara Corp エキシマレーザ装置
EP1119082A3 (fr) * 2000-01-18 2004-05-26 Ushiodenki Kabushiki Kaisha Ventilateur à courant transversal pour un laser à gaz excité par décharge
JP2002345210A (ja) * 2001-05-11 2002-11-29 Ebara Corp 電動機装置及びエキシマレーザ装置
JP4656058B2 (ja) * 2004-04-21 2011-03-23 三菱電機株式会社 ガスレーザ発振器およびガスレーザ加工機
JP6063199B2 (ja) * 2012-10-15 2017-01-18 ギガフォトン株式会社 放電励起式ガスレーザ装置
CN114183468B (zh) * 2021-12-08 2022-11-15 珠海格力电器股份有限公司 压缩机、空调器
CN114183932A (zh) * 2021-12-17 2022-03-15 珠海格力电器股份有限公司 一种燃气热水器、风机转速检测方法及装置

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US5586134A (en) * 1992-11-13 1996-12-17 Cymer Laser Technologies Excimer laser
US5770933A (en) 1996-01-31 1998-06-23 Cymer, Inc. Blower motor with adjustable timing
US6026103A (en) * 1999-04-13 2000-02-15 Cymer, Inc. Gas discharge laser with roller bearings and stable magnetic axial positioning

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US5586134A (en) * 1992-11-13 1996-12-17 Cymer Laser Technologies Excimer laser
US5770933A (en) 1996-01-31 1998-06-23 Cymer, Inc. Blower motor with adjustable timing
US6026103A (en) * 1999-04-13 2000-02-15 Cymer, Inc. Gas discharge laser with roller bearings and stable magnetic axial positioning

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6519273B2 (en) * 2000-02-21 2003-02-11 Ebara Corporation Magnetic bearing and circulation fan apparatus
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CN108352674B (zh) * 2015-12-01 2020-05-19 极光先进雷射株式会社 准分子激光装置
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JP3766230B2 (ja) 2006-04-12
DE60040256D1 (de) 2008-10-30
EP1047162A3 (fr) 2003-10-01
JP2000307175A (ja) 2000-11-02
EP1047162B1 (fr) 2008-09-17
EP1047162A2 (fr) 2000-10-25
KR20000077056A (ko) 2000-12-26
TW444423B (en) 2001-07-01
KR100654409B1 (ko) 2006-12-05

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